Pest and Disease Control for Edible Fungi and Hybrid Breeding Techniques for Large-Flowered Clivia

All over the country, especially in large and medium-sized cities such as Changchun, Qingdao and Nanjing, people are actively exploring good ways to cultivate prized specimens. Through several years of cultivation, propagation and observation, the author has mastered a set of manual hybrid propagation techniques, which are introduced

as follows.

Selecting the Male and Female Parents

Select the male and female parents by choosing the best among the best according to the standard criteria for prized clivia. The probability of prized specimens appearing among the offspring will then be much greater. Keep the selected male and female parents isolated from other plants for care, attach labels with their names, and record

them for the files.

Flowering Period Management

Apart from the same management given to other clivias, the selected male and female parents also need regular extra applications of phosphorus and potassium fertilizer to ensure robust plant growth. Because they grow in a greenhouse all year round, the flowering period mostly falls in winter and early spring. The optimum temperature

during the flowering period is 15°C-25°C, which favours scape emergence; it is generally kept at around 20°C, and the lighting time is increased. Especially on cloudy days or at night, adding illumination with incandescent lamps or agricultural fluorescent lamps will make the flowers larger and more brightly coloured, and the flowering period will last more than half a month.

At the beginning of flowering, apply one topdressing of phosphorus and potassium fertilizer, which helps raise the fruit-setting rate.

Hand Pollination

(1) Preparation: prepare clean pollination tools such as tweezers, small medicine bottles and small brushes.

(2) Timing of pollination: when a single floret has been open for 2-3 days, the pollen of the stamens is mature.

After the flower opens, pollination is best done when the three-forked stigma of the pistil secretes sticky fluid.

The pollination time is 9-11 a.m. or 1-3 p.m. on a sunny day, and it is repeated once the next day; at this time sunlight is abundant, which raises the seed-setting rate.

Pollination Method

(1) When the female parent's flower has just opened, first carefully remove all the stamens' anthers with tweezers to prevent self-pollination.

(2) When the male parent's flower has been open for 2-3 days and the stamen pollen is mature, use tweezers to pick off the anthers, gather those from the same male parent into one small medicine bottle, label it with the name and set it aside for use.

(3) Dip a small brush into the pollen in the labelled small medicine bottle and, according to the pollination time, gently dab it directly onto the three-forked stigma of the female parent's pistil, then label it with the name and put up a marker, keep detailed records for the files, and ensure the male parent is pure; pollination is then complete.

Seed Selection

It takes 9 months from pollination to fruit maturity for the female parent clivia. During this period it must be managed much more meticulously than ordinary clivia; frequent observation is needed to ensure the female parent grows robustly and is free of pests and diseases. When the fruit turns from green to red or purplish red

and the fruit is hard, it indicates that the seeds have matured. At this point cut off the whole fruit scape and place it in a light and airy place; after a post-ripening process of nearly one month (if placed in a constant-temperature cabinet at 0°C, the post-ripening process can be completed half a month earlier), peel off

the fruit skin and select plump seeds with a bud eye for raising seedlings.

Raising Seedlings

The time for raising clivia seedlings. Seedlings can be raised once the post-ripening process is complete, generally from November to February of the following year.

(1) Making a hotbed: generally made with small-hole plastic basket containers that are easy to move and no more than 10cm deep.

(2) Raising seedlings in wood shavings (good water and air permeability): choose shavings of linden and oak wood, wash them clean, put them on the hotbed and spread them level; arrange seeds from the same female and male parents neatly with the bud eye facing down, at a spacing of 2-3cm, on the same

hotbed, then cover the seeds with another layer of wood shavings, also 2-3cm thick, so that after covering, the wood shavings are about 2cm below the upper rim of the hotbed; then water thoroughly and keep the temperature between 20°C-25°C, spraying once every 3-5 days with water at the same temperature as the greenhouse.

Generally the radicle appears 7-10 days after sowing, and the first true leaf grows after one month, indicating that the offspring plant has begun to develop on its own.

Seedling Stage Management

Young seedlings like light; the temperature is generally kept between 18°C-25°C. Before the second true leaf appears, carry out hardening of the seedlings for half a month at a temperature of 18°C-20°C; after the two true leaves have grown, they can be transplanted from the hotbed into flower pots.

within.

(1) Potting soil selection: for cultivating clivia, the best potting soil is a mixed soil of broadleaf oak and chestnut leaf mould, coniferous black pine leaf mould and furnace ash slag, with a small amount of bone meal or roasted small hemp seeds added; it has the characteristics of being loose, airy

and fertile, which favours the growth and development of the fleshy roots.

(2) Watering: after potting, pour water in from the rim of the pot, and never pour it into the heart leaves. If watering is improper and water remains in the heart leaves, just absorb it away with absorbent cotton or toilet paper.

(3) Sun protection: in summer, cover the greenhouse with a sunshade net to prevent direct sunlight.

(4) Ventilation: as the temperature rises, continuously increase the amount of ventilation, which helps lower the temperature and harden the seedlings.

(5) Topdressing: fertilizer can be applied right after potting (mainly phosphorus and potassium fertilizer), but the concentration must be low, generally topdressing once every half a month.

(6) Pest and disease control: in the hot and humid summer season, improper management makes clivia highly prone to anthracnose and bacterial soft rot. Therefore, attention must be paid to improving the environment, strengthening ventilation, not watering too much, and never allowing water to remain in the heart

leaves; apply less nitrogen fertilizer and appropriately increase phosphorus and potassium fertilizer to enhance the plant's disease resistance. Diseased leaves and lesions found should be cut off promptly, burned or buried deep, and fungicides sprayed for chemical control.

Under normal circumstances, seedlings in one year of growth have 4-6 true leaves, and after three years, when they reach 11-13 true leaves, they begin to flower and bear fruit. Finally, according to the development process of the offspring, further screen the good and the poor, and do the work of breeding new varieties

well.